S
M
T
W
T
F
S
29
63°
42°
30
65°
33°
1
51°
28°
2
48°
27°
3
52°
35°
4
55°
38°
5
51°
34°
6
49°
30°
7
50°
26°
8
46°
25°
9
47°
25°
10
47°
28°
11
51°
28°
12
55°
33°
13
53°
33°
14
51°
29°
15
49°
27°
16
48°
30°
17
47°
27°
18
46°
23°
19
45°
22°
20
45°
24°
21
48°
27°
22
53°
26°
23
46°
23°
24
43°
22°
25
43°
24°
26
44°
28°
27
45°
25°
28
46°
25°
29
46°
24°
30
45°
25°
31
47°
22°
1
44°
23°
2
45°
30°
Temperature Graph
°F
Avg. Hi
Avg. Lo
Actual Hi
Actual Lo
Forecast Hi
Forecast Lo
December Weather in Marietta
Marietta's December 2026 forecast shows daily high temperatures ranging from 43° to 65°, with overnight lows between 22° and 42°. The average high for December is 49° with an average low of 28°. AccuWeather's monthly forecast extends further ahead than any other source, with day-by-day RealFeel® Temperatures giving a complete picture of how December weather will actually feel in Marietta. See also: January | February | March.
